1. Technical Field
This invention relates generally to gas turbine engines and particularly to a gas turbine engine seal.
2. Background Information
In the construction of gas turbine engines, it is often necessary to provide seals between adjacent hardware components to prevent or control leakage of fluids between such components. For example, it is crucial that effective sealing be provided in the flow path for gas turbine engine compressor discharge cooling air. The turbine section of a gas turbine engine operates at temperatures well above 1,000° C. To minimize thermal degradation of turbine components, it is necessary to internally cool such components with the engine's compressor discharge air. Such compressor discharge cooling air is unavailable to support the combustion of fuel in the engine's combustor. Therefore, it is crucial that the flow of such compressor discharge cooling air be precisely controlled at least in part by appropriate sealing techniques. Use of excess compressor discharge cooling air beyond what is required for adequate cooling of the engine's components can lower the overall efficiency of the engine.
The prior art discloses several arrangements for sealing gas turbine engine components. A well-known arrangement for sealing gas turbine engine components involves the disposition of flexible seals such as rope seals or the like within a component groove or slot. Such prior art sealing arrangements have met with only limited success due to the harsh environment within which such gas turbine engine components must operate. For example, the extreme temperatures encountered by turbine components cause thermal expansion and contraction of such components. Extreme working fluid pressures encountered by engine components can cause unintended movement thereof. Such movement and thermal expansion and contraction of the components can result in loosening of the sealing elements within the slots and even migration of the seal elements from the slots. Moreover, the harsh environment encountered by such seals can result in deformation of the seals thereby compromising the effectiveness of the seals. Accordingly, it remains a challenge to effectively seal gas turbine engine components within harsh environments encountered by such engine components.